UK's tidal river tech to provide water to southern areas

09:40, June 03, 2011

A multi-million pound scheme to improve water supply in an area of increasing demand in the southern region of the United Kingdom includes new tidal river extraction technology and the construction of a water company's first storage reservoir in 40 years.

The new lagoon will be located at Hardham in Sussex, where a new pumping station is also under construction from the tidal River Arun.

This neat solution to the ever-growing demand for water came from developing a better understanding of the movement of the saline water in the nearby tidal river.

In the past it has been typical for river abstraction points to be situated at the bottom of catchments, above the tidal stretches.

In this innovative project, it has been proven possible because of advances in technology, including numerical modeling, line control and monitoring systems, for the Southern Water Company to situate its abstractions in the tidal part of the river, crucially within the zone in which the freshwater fluctuates in height but not in saline quality.

The lagoon will have a capacity of 75 million liters. Modern technology is employed through monitors and sensors placed in the river bank that will trigger a flow of information about the amount of river flow and when it is opportune to abstract the water.

This will be a possibility perhaps twice in a 24-hour period and action has to be fast-timed with information relayed back to the pumping station.

Through this system, it will be possible to pump up to 10 million liters a day from the River Arun and carry it to the lagoon by way of the new 1.8-kilometer pipeline being constructed.

Great care has been taken to ensure that the water storage lagoon will fit in with the natural beauty of the surrounding countryside. New grassland, bushes and hedges will be planted, including a special type of grass that will help strengthen the banks of the lagoon.

The location where water is to be abstracted from the river was investigated several times to ensure that it caused the least impact on the environment.

A site owned by the Royal Society for Protection of Birds is among the close neighbors and all work carried out has been done with the intent of preserving the habitat.

The project started with the first meetings in April 2005, construction began in April 2010 and is expected to be completed in March 2012. Southern Water will invest 200 million pounds in its water resource program in the next five years.

Meyrick Gough, Southern Water's resources manager, said: "I am very pleased with this new source of water for our area. This scheme is one of the final pieces of the jigsaw in a series of schemes that we have been investing in over the last five years to improve resources.

Gough continued: "The team that has worked on this job is doing a fantastic job using technology to find the most sustainable solution. I believe that the structured approach and the careful citing of abstractions in tidal waters could actually be used beneficially in other countries."